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Hypermetabolism in mice caused by the central action of an unliganded thyroid hormone receptor α1
Author(s) -
Sjögren Maria,
Alkemade Anneke,
Mittag Jens,
Nordström Kristina,
Katz Abram,
Rozell Björn,
Westerblad Håkan,
Arner Anders,
Vennström Björn
Publication year - 2007
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601882
Subject(s) - hypermetabolism , biology , thyroid , thyroid hormone receptor , endocrinology , medicine , hormone , thyroid hormone receptor beta , receptor , nuclear receptor , hormone receptor , genetics , transcription factor , gene , cancer , breast cancer
Thyroid hormone, via its nuclear receptors TRα and TRβ, controls metabolism by acting locally in peripheral tissues and centrally by regulating sympathetic signaling. We have defined aporeceptor regulation of metabolism by using mice heterozygous for a mutant TRα1 with low affinity to T3. The animals were hypermetabolic, showing strongly reduced fat depots, hyperphagia and resistance to diet‐induced obesity accompanied by induction of genes involved in glucose handling and fatty acid metabolism in liver and adipose tissues. Increased lipid mobilization and β‐oxidation occurred in adipose tissues, whereas blockade of sympathetic signaling to brown adipose tissue normalized the metabolic phenotype despite a continued perturbed hormone signaling in this cell type. The results define a novel and important role for the TRα1 aporeceptor in governing metabolic homeostasis. Furthermore, the data demonstrate that a nuclear hormone receptor affecting sympathetic signaling can override its autonomous effects in peripheral tissues.